Still trying to master acrylic. Still not happy and need help!

[ColdBlooded]

I have been experimenting with different bits cutting .177 and .22 clear and black acrylics. Trying to get a cut that will not require edge prep before gluing. So far I have not been happy. I will list the bits I have used and a 1 - 10 rating on the edge finish. 10 being the best. Does anyone have any other suggestion in my quest for a perfect 10? I have tried many different speed/feed with these bits and have not had much of a difference in edge quality. I am using vacume hold down, pressure foot and just to make sure my stock is not moving at all spray adhesive.

Harvey Tool

Plastic Single "O" Flute Up Cut 1/8" # 51508 my rating 6
Plastic Single "O" Flute Up Cut 3/16" # 51212 my rating 5
Plastic End Mill Up Cut Spiral 2 Flute 3/16" # 48712 my rating 3
Plastic End Mill Strait 2 Flute 3/16" # 14612 my rating 7 (best bit overall, so far)

Amana Tool

Plastic Single "O" Flute Up Cut 1/8" # 51410 my rating 6
Plastic Single "O" Flute Up Cut 3/16" # 51412 my rating 6

Onsrud

Acrylic Single "O" Flute Up Cut 1/8" # 63515 my rating 6
Acrylic Single "O" Flute Up Cut 3/16" # 63520 my rating 5

If you have another bit recommendation please list model # and the speed/feed you are using to get the best edge finish.

2nd problem

I am also using a Amana Tool In-Groove CNC Insert Engraving Tool with 90° V-Tip Engraving Insert Knife / 0.04" tip width. Does anyone have any tips for speed/feed to get a clean cut .02" deep engraving in acrylic without the white tool marks.

Thanks for the help.


Thanks,

Brendan

[jerry_stanek]

I watched this video and learned some about cutting different materials. Speed and feed with what cutters.

http://www.youtube.com/watch?v=_b5I3H2Hp6M

[steve_g]

Brendan:

I have success with just about anybody's "O" flute. Cast and extruded Acrylic cut entirely different, and clear cuts different than black. you just have to play with speeds to see what works with this manufacture or that one. That said, I still have to use a medium bodied solvent cement.

Good luck!

Steve

[ColdBlooded]

Thanks for the video. All of the acrylic being cut in the video was then followed up by a Mono-Crystaline Daimond Pollisher. Guess I am getting the best cut I can, just never thought of using a 2nd tool to clean up the edge. Looks like I will be ordering some new tooling today. Again thanks for the video. Have you used a polishing tool yourself? Do you use the same tool path or a finishing path after your cut?@

[ColdBlooded]

I take that back, at $1800 for 1 bit I will keep looking for a better cutting tool. WOW! Is there anyother finishing tool options out there?

[jerry_stanek]

I should have mentioned that I checked on the price about a year age and it was about $1500.

[Brady Watson]

Give an Onsrud 3-flute finisher a try. It is an upcut spiral O flute with 3 cutting edges. Works lovely in soft PVC to acrylics. Go 3/8" on the diameter unless you really need to go smaller. Make sure your machine is clean & tight and that you have an excellent hold down on the material.

-B

[jerry_stanek]

At work we use a 1/2 vortex bit

[Rick W]

Hey Brendon,

Try your #7 bit
Plastic End Mill Strait 2 Flute 3/16" # 14612 my rating 7 (best bit overall, so far)

Cut the piece out two times (the first time don't go all the way through or use tabs whatever to hold the piece in place). On your second cut take off a hair
(make sure you cut in the right direction on your second cut). Basically what you will be doing is creating space so your bit isn't cutting on both sides creating friction. I've cut a 3" letter A out of 1/8" plexi (extruded) using a cheap cobalt two flute 1/8" down spirol (one pass 2 depths) MS .75,.5 depth.0625 per pass.
Hope this helps and is explained properly.

[ColdBlooded]

Hey Brady, thanks for the suggestion. Do you have a series # or model # for your recommended finisher? Harvey Tool has what looks like Onsruds Diamond Finisher ($1800) for only $180. Have you ever worked with these tools? The video shows it finishing a very nice edge. If they really work that good it may be worth the $1800. Just don't want to gamble.